Method and apparatus for making edge-wound coils



" 1 .927. May r e. H. WHITTiNGHAM METHOD AND. APPARATUS FOR MAKING EDGEYIOUND POILS- 3 Sheets-Sheet 1 Filed Da e. 11, 1925' y 1927 G. H. WHITTINGHAM METHOD AND APPARATUS FOR MAKING EDGEWOUND COILS Filed Dec. 11, 1925 s Sheets-Sheet 2 1927' G. H. WHITTINGHAM METHOD AND APPARATUS FOR MAKING EDGEWOUND COIL-S Filed Dec. 11. 1925 25 Sheets-Sheet 3 Patented May 31, 1927. I

v UNITED STATES PATENT OFFICE.

GEORGE E. WHITTINGHAM. OF BALTIMORE, MARYLAND, ASSIGNOR TO MONITOR Coll- TROLLER COMPANY, OF BALTIMORE, MARYLAND, A CORPORATION OF MARYLAND.

METHOD AND APPARATUS FOR MAKING EDGE-WOUND COILS.

Application filed December 11, 1925. Serial No. 74,733.

This invention relates to a machine for and method of winding fiat metal ribbons on edge. In carrying out the invention, I provide a, machine, which may be an ordinary lathe, having a relativelylong bed and having a slide-rest which is carried along the bed*b the feed screw and which may be manua ly moved back and forth on the rails by the rack and pinion devices usually found on lathes. A relatively long core-bar is gripped in the chuck and is revolved by the machine, and upon the slide-rest is arranged a die supporting member carrying dies which co-operate with the bar to coil the ribbon on edge around the bar in evenly spaced convolutions. To start the operation of winding the coil, one end'of the ribbon is passed through the die and is secured to the chuck, and certain adjustments are necessary in order that the die may coil the ribbon smoothly and accurately.

The invention is designed particularly for winding coils from ribbons of resistance metal, to be used in rheostats, which metal is usually of alloy and more or less resilient. Where the convolutions of the coil are spaced say one-quarter of an inch or more apart, a've limited length of the coiled ribbon woul extend the length of the corebar. In order to wind a greaterlength of ribbon on the core-bar, the machine is stopped after the slide-rest and dies have traveled approximately the full length of the bar and the core-bar is reversed sufliciently to slacken the grip of the coil on the bar. The slide-rest and die are then manually moved back toward the chuck, pressing the convolutions of the coil together. The machine is then started and the part" of the coil which has been formed and com" pressed grips the bar and does not ex and and another length of coil with space volutions is formed as theslide-rest an move to the end of the bar. This lat 1' length of coilyl-is then compressed in the same mannerasthe first length, and another shorter length is wound upon the bar. These operations of winding and compressing the convolutions are repeated until the core-bar is practicallyieovered with closely arranged convolutions, when the ribbonis severed and after the severed end has been drawn through the die, the 'motor is stopped and the die is moved be 0nd the end 0 the bar. This movement oft e die permits the "coiled assembled and compressed ribbon to expand, and the coil by its own resiliency discharges itself from the bar, except for a part which may be readily pulled off of the bar. Thus, by the method described, a coil which may be several times the length of the core-bar may be made without going through the settingup operation or cutting the ribbon more than once.

In the accompanying drawing,

Fig. 1 is a top plan view of the machine for winding the coils, showin the, die in the position for starting the win ing operation;

Fig. 2 is a similar view, the die being shown in position to commence a second operation;

Fig. 3 is a erspective view of the die supporting mem ers and dies, separated;

Fig. 4 is a Fig. 5 is a similar view of one of the dies;

perspective view of the same,

Fig. 6is a section on the line 66 of Fig.

1, showing the rear side of the die support anda portion of the 'face plate of the chuck in elevation;

Fig. 7 is a section on the line 7-7 of Fig. 1;

Fig. 8 is a section through the die holder and dies, taken on the line 88 ofFig. 7; I

Fig. 9 is a top plan View of the die holder and of the face plate of the chuck, partly broken away, showing the metal ribbon attached to the face late and with the tightscrews with rawn from the horn of enm the ie plate, the parts being shown in position to commence winding the coil; and,

Fig. 10 is a similar view, showing the coil partly wound and with the horn of the shoe clamped. against the metal ribbon.

Referringt-o the drawing, a indicates a machine for winding the 'coils and which rdinary lathe havinga slide-rest 1, withft usual screw feed for moving the rest along the rails 2 andwith the usual rack and pinion for returning the rest. The rails of the machine are relatively long, and a round bar 3, which forms a COIQjOII which to wind the coils, is secured at oneiend withina suitable chuck 4, and supported at its opposite end in a tail stock 5 which is adjustable along the rails. A motor is shown at '6 for turning the chuck, the gearing between the motor and the chuck being omitted because any desired arrangement of gearing may be provided. The chuck,

in this instance, is shown as a hub having a set screw-7 fr securing the,bar 3 within the hub, and uponthehub isa suitable face plate 8, to which one end of the ribbon 9, from which the coil is formed, is secured. Upon the slide-rest is suitabl secured a diehoilger b, carrying the dies or forming'the co The structure of the dies and die-holding members is shown in Figs. 3-10, inclusive. The die-holder comprises a supporting member 10, which is bolted to the slide-rest and has a hub or boss 10*,v provided with an opening 10 through which. the shaft or mandrel 3 extends. A socket 10 is formed in the hub, concentric with the opening 10", and the face 10 of the hub, surrounding the socket, is helically formed, as shown. Within the socket is arran ed a cylindrical hardened steel. die 0, whic surrounds the shaft or mandrel 3, and the exposed end 11 of-said die is helically formed. Set screws 12, extending through the rear wall of the socket, bear against'the die 0, and by means of these screwsthe die may be adjusted to take up wear and to suit the thickness of the metal ribbon which is to be wound. The die 0 has a flattened portion 11 on its lower side, and a hardened steel guide strip 13 1s fitted into a groove 10 in the support 10 and extends horizontally below the die a, andthe flattened portion 11 of the die rests upon this guide strip. The guide strip projects beyond the face of the support 10 and enters'a groove 14 in a die; plate d, which is secured to the hub by screws 15, below the guide strip 13. The lower part of the die plate d is substantially flat and rests against the lower flat portion of the hub 10, while the upper portion 16 of the plate is in the form of a helically arranged born. The die plate has a central opening 17, through tends, and surrounding arranged within a shallow socket this opening is a helical die e,

which is opposed to the die 0 when the plate d is clamped. to the hub. In addition to the screws 15, for securing the base of the plate to the base of the hub, a series of screws 18 is provided for adjusting the horn ofthe plate toward and from the helical face of i the hub. As shown, these screws are spaced apart around the socket in the hub and ex in 's- 19 in t e horn of the plate.

. n starting the winding operation, the slide-rest 1 is moved to-bring the die-holder close to the face plate 8 of the machine, as shown-in Figs. 1 and 9. The adjusting screws 18 are turned backward so that they ill be free from the'plate d, as shown in 9, and will not obstruct the gap be-. the plate and the hub. One end of the Fig. tween flat ribbon 9, from which the coilis to be niade,'is inserted in the slot 8, be

guide strip 13,

as shown in Fig.

which the mandrel or core-bar exthe hub into threaded open tween the plate and the hub and above the and this end portion of the ribbon is pushed through the slot. The end 9 of the ribbon is then turned over at a right angle and inserted inanfopening in the face plate 8 of the-machine and secured in-the opening by a wedge 20. The machine is then started and the face plate carries the end of the ribbon around, as indicated in dotted lines in Fig. 7, and when the end portion of the ribbon hasbeen carried beyond the line of the last clamping screw 18 in the series, the machine is stopped. In this operation, the face plate of the machine has made slightly more than a half revolution, to carry the end of the ribbon past the clampfor the horn of the die plate. The

ing screws screws 18 are then tightened to hold the horn of the die plate firmly against theribbon and the machine is then started, further adjustment of the screws '18 and 12 being made, if necessary, after the core-bar or mandrel has made afew revolutions. The I winding of the metal ribbon causes the 1 straight portion of the-ribbon immediately below the core-bar to bear against the guide strip 13 and therefore this strip is made of hardened steel to resist wear. As the screw feed of the machine carries the slide-rest and thedie carrier awa from the face late ofthe machine, the ri bon is coiled a out the core-bar in evenly spaced convolutions, 10. When the slide-rest reaches the right hand end of. the machine, as indicated in dotted lines in Fig. 1, the-core bar will be filled with the spaced convolutions of the coil, as'indicated at f in Fig. 1.

The machine is then stopped and the motor is reversed sufiiciently to cause the coil to release its grip on the core-bar; .One or two revolutions of the bar is enough for this purpose. The slide rest is then moved toward the face plate until the spaced convolutions of the coil are all brought together, as. shown at f in Fig. 2.I The motor is then started, and as it starts,-th e convolutions f tighten on the core bar andremain in close contact with one another and another section of coil f is formed on the'bar, with its convolutions spaced apart. When the slide-rest reaches the right hand position shown in The part of the ribbon which is being fed 3 to the machine is then severed close to the die, and when this end portion has been .dotted lines in Fig. 2, the motor is again stopped and reversed-sufficiently to loosen the grip of the coil on the bar and the sliderest is again moved to'the left to compress the spaced eated until the core bar is filled w'ound upon the core-bar'the motor is sto .The tail stock 5 is then moved to t e right, beyond the core-bar, andthe slidel s t s also m v d to the right until the die carrier is moved beyond the end of the bar.- As soon as the die carrier has moved beyond the end of the bar, the greater part of the coil automatically discharges itself from the bar by its own expansive force, and the re mainder of the coil can then be pulled oil of the bar.

What I claim is: 1. In a machine for winding flat" metal ribbons on edge, a core-bar and means for rotating the safne, a die-support and means for moving the same along the bar, a die carried by said support and closely surrounding the bar, said die having a helically formed end, a die-plate having a portion secured to said support and having a helically formed horn spaced from the support and extending around the bar parallel with the helical end'of said die, and removable means for drawing said horn toward said support. 2. In a machine for winding flat metal ribbons on edge, a core-bar and means for rotating the same, a die-support and means for moving the same along the bar, a die carried by said support and closely surrounding the bar, said die having a helically formed end, a die-plate having a ortion secured to said support and having a elically formed horn spaced from the support and extending around the bar parallel with the helical end of said die, and means for adjusting said die toward saidplate.

3. In a machine for winding fiat metal ribbons on edge, a core-bar andmeans 'for rotating the same, a die-support and means for moving the same along the bar, a' die carried by said support and closely surrounding the bar, said die having a helically formed end, a die-plate having a portion secured to said support-and having a helically formed horn spaced from the support and extending around the bar parallel with the helical end of-said die, a helically formed die carried by said plate and opposed to the die in said support, and removable means for .drawing said horn toward said support.

4. In a machine for winding flat metal ribbons on edge, a core-bar and means for rotating the same, a die-support and'means 50 to ;moving the same along the bar, said rt having a socket surrounding the a} die mounted within the socket and p surrounding the bar, said die having a a helically formed end, a die-plate having 55 a portion 'secured to said support and hav- 'ing aa- -helically formed horn spaced from the supportand extending around the bar parallel with the helical end of said die, and removable means for drawing said horn toward said support.

5. In a machine for winding flat metal lribbons on edge, a core-bar and means for rotating the same, a die support and means- L for moving the same along the bar, a die carried by said support and closely surrounding the bar, said diehaving a helically I formed end, a die-plate secured to said support and having a helically formed horn extending around the bar parallel with the helical end of said die and spaced therefrom, and a series-of adjusting screws spaced apart around the horn for drawing said horn toward the support, said screws being removable from the spacebetween the horn and the support.-

6. In a machine for winding flat '1netal ribbons on edge, a core-bar and means for rotating the same, a die support and means for moving the same along the bar, a die carried by said support and closely surrounding the bar, said die having a helically 3 formed end, a die-plate secured to said support and having a helically formed horn extending around the 'bar parallel with the helical end of said die and spaced therefrom,

a series of adjusting screws spaced apart around the horn for drawing said horn toward the support, said screws being removable from the space between the horn and the support, and a series of adjusting screws spaced apart around the die for adjusting the latter-toward the plate.

7. In a-machine for winding fiat metal ribbons on edge, a core-bar and means for revolvingthe same, a die-holder movable along the bar, a die in said holder surrounding the bar and having a'helical end, a plate secured to said holder and having a helical horn opposed to said di'e,'and a hardened guide strip arranged between said holder and plate and arranged tangentially to the die.

8. In a machine for winding fiat metal ribbons on edge, a core-bar and means for revolving the same, a die-holder movable along the bar, a die in said holder surrounding the bar and having a helical end, a Y

plate secured to said holder and having helical horn opposed to said die, and a hardened guide strip fitting within grooves in the holder and plate and extending tangen tially to the die.

9. The method of coiling flat metal ribbons on edge which comprises extending one end of the ribbon through a coiling die and securin said end to a core-bar, rotating said bar an moving said die along the bar until the latter is substantially lilled with spaced convolutions of the coil, stopping and reversing the motion of the core-bar sufficiently to release the grip of said convolutions on the bar, moving the die backward to compress the convolutions, rotating the bar ;and moving the die to wind further spaced convolutions on the bar, again stopping and reversing the core-bar and moving the die to compress the latter spaced convolutions together, and repeating these operations until the-bar. is substantially full of compressed convolutions, and then removing the die from I her and securing said end to a core bar having a driving member at one end, rotating said bar and moving said die member along the bar until the major part of the latter is filled with spaced convolutions of the coil,

v stopping the motion of the core bar and releasing the grip of the coil on the bar, moving the die member backward to compress the 'convolutions, rotating the bar and moving the die memberto wind further spaced convolutions on the bar, again stopping the bar, releasing the grip of the coil on the bar and moving the die member to compress the latter spaced convolutions together, and repeating these operations until the major part of the bar is full of compressed convolutions, and. then removing one of said members from the core bar to permit the coil to expand anddischarge from the bar.

In testimony whereof I hereunto afiix my signature.

GEORGE H. WHITTINGHAM. 

